Authors : R.K. Kyuma, R.G. Wahome, J.M. Kinama and V.O. Wasonga
Abstract: Above-ground biomass and carbon stocks of Prosopis juliflora were estimated using allometric equations in floodplains and hillslopes landscapes of the drylands of Magadi in Kajiado, Kenya. Three hundred and twenty Prosopis trees were sampled, out of which one hundred and twenty eight were randomly selected and used for the development of the allometric equations. Basal diameter, diameter at breast height, crown width and tree heights were measured; and their fresh weights taken for the development of Prosopis biomass prediction models. Cubic and power models yielded better results than linear models in biomass prediction with basal diameter being more reliable than diameter at breast height, crown width and height. Cubic curvilinear and power models for biomass prediction returned the better R2 values (0.82 and 0.98) for single and multistemmed Prosopis trees respectively. Validation of models revealed significant correlation between predicted and measured tree biomass, suggesting effectiveness of the models in biomass predictions. The dense and managed plots in the hilllslopes had the highest Prosopis biomass (44.13 tons ha–1) followed by dense and unmanaged plots (43.68 tons ha–1). The dense and unmanaged plots of the floodplains had lower estimates (34.15 tons ha–1) followed by dense and managed (28.01 tons ha–1). The moderately and sparsely dense plots in both landscapes recorded lower biomass (18.75 and 3.47 tons ha–1 in hillslopes and 12.72 and 5.09 tons ha–1 in floodplains). The effects of management were not significant in both the hillslopes and floodplains. There was growth in the Prosopis biomass trends in the dense and unmanaged Prosopis clusters but there was no change of in the moderately dense and the sparsely dense clusters during the period of study. There were insignificant differences in biomass productivity between the dense managed Prosopis plots and the dense unmanaged prosopis plots in the hillslope landscape, although, the biomass in the dense managed plots were consistently higher than in the unmanaged. In the floodplains landscape, the biomass for the dense managed Prosopis plots was consistently lower than the dense unmanaged Prosopis plots but the differences were also insignificant. Further studies were recommended with longer time frames of observations to assess the effect of management on biomass production.
R.K. Kyuma, R.G. Wahome, J.M. Kinama and V.O. Wasonga, 2019. Estimating Above-Round Biomass and Carbon Stocks of Prosopis juliflora using Allometric Equations in Drylands of Magadi, Kenya. Environmental Research Journal, 13: 88-97.